Low yields of fingerprint-recognition chips and LCD driver ICs will likely force Apple to reduce first-quarter shipments of the rumored iPhone 5S, which is slated for launch in September 2013, the Taiwanese web site Digitimes.com reported today.

Production of fingerprint-recognition and LCD driver chips for the iPhone 5S should have started at the end of June or early in July, but issues related to yield rates will delay commercial production of the two chips to the end of July, the web site reported explained.

iPhone 5S' fingerprint recognition chip is designed by AhthenTec, of which Apple acquired in July 2012. Issues related to the original design of the chip reportedly caused the lower yield rates, claimed the sources, adding that Apple outsources the production of the fingerprint recognition chips to Taiwan Semiconductor Manufacturing Company (TSMC) and the packaging of the chips to Xintec.

About three million units of the initial shipments of iPhone 5S will be delayed to the fourth quarter, indicated the sources.